Rod drive unit for a sewer cleaning machine



Oct. 15, 1963 B. L. SIEGAL 3,106,734

ROD DRIVE UNIT FOR A SEWER CLEANING MACHINE Filed Dec. 31, 1962 4 Sheets-Sheet 1 INVENTOR.

BURTON L. SIEGAL A T TOR/V67 B. L. SIEGAL 3,106,734 ROD DRIVE UNIT FOR A SEWER CLEANING MACHINE Oct. 15, 1963 4 Sheets-Sheet 2 Filed Dec. 31, 1962 gi Q BURTON L. SIEGAL ATTORNEY Oct. 15, 1963 B. L. SIEGAL ROD DRIVE UNIT FOR A SEWER CLEANING MACHINE Filed Dec. 31, 1962 4 Sheets-Sheet- 3 Q E i I'lllllnlull INVENTOR. BUR 701V L 5/5 614i ATTORNEY Oct. 15, 1963 B. L. SIEGAL 3,106,734

ROD DRIVE UNIT FOR A SEWER CLEANING MACHINE I Filed Dec. 31, 1962 4 Sheets-Sheet 4 I E- Y i u I 172 fiP LZ R. H /62 405 r lnlmllll q 4g '68 i V F I04 \z\ x Amok "IMHHIUH I 7 WIMIHJIII' BURTON L. S/EGAL ATTORNEY United States Patent Office 3,106,734 Patented Oct. 15, 1963 3,106,734 ROD DRIVE UNIT FQR A SEWER CLEANING MACK-ENE Burton L. Siegal, Chicago, 111., assignor to OBrien Manufacturing Corporation, Chicago, IlL, a corporation of Illinois Filed Dec. 31, 1962, Ser. No. 248,802 16 Claims. (Cl. 15-1042,)

The improved drive unit comprising the present invention has been designed for use primarily in connection with a sewer cleaning machine of the type which is commonly referred to as a sewer rodder and wherein there is embodied reversible power-actuated means for feeding a composite flexible steel sewer cleaning rod into a sewer pipe and for retracting the rod from the pipe.

A composite sewer cleaning rod of the type With which the present drive unit is concerned is of fairly standardized design and consists of a series of individual rod lengths or sections and couplers between the adjacent ends of the rod sections. The rod sections are manufactured in standard lengths, usually in multiples of one foot, and although they may not in themselves exhibit a marked degree of flexibility when they are coupled to gether to produce a composite sewer rod of great length, the rod as a whole is sutficiently flexible that it may be coiled or reeled for storage either in or out of the associated machine. Such a composite sewer rod is put to use by pushing it into or pulling it from a pipe to be cleaned, while at the same time, effecting rotation of the rod so that a boring or other sewer-penetrating tool which is carried at the leading end of the rod may become efiective within the sewer pipe to loosen the material and thus pave the way for further and progressive entry of the rod into the pipe.

At the present time, there is on the market a sewer cleaning machine which comprises a wheeled vehicle, either self-propelled or tractor drawn, and wherein a comparatively great length of composite sewer rod is normally stored in a rotatable cage-like receptacle in a coiled condition. The rod is capable of being fed from or returned to the rotating cage, and rotation of the cage is relied upon to effect the necessary rod rotation during sewer cleaning operations. A reversible powered drive unit is employed to effect longitudinal endwise movement of the rotating composite sewer rod, and this drive unit embodies an endless series of pusher blocks which are carried on an endless chain conveyor and have forked yoke portions that loosely straddle successive rod sections as they move into a straightaway or reach section of the conveyor and slide along the rod sections until such time as they engage the couplers, at which time they force the couplers in one direction or the other without affecting their rotation and thus effect longitudinal shifting of the rotating composite rod in the desired direction. It is to this particular type of sewer cleaning machine or rodder that the present invention specifically relates.

Heretofore, in conneotionwith a conventional sewer cleaning machine of the aforementioned type or character, little consideration has been given to effective register of the various moving pusher blocks with the couplers of the composite rod in the area of the rod being operated upon, i.e., within the effective operating area of the drive unit. When changing from a forward rod-feeding motion to a reverse rod-coiling motion, considerable lost motion is encountered before an individual pusher block will move into effective engagement with an adjacent coupler. Furthermore, especially where the couplers are employed for coupling rod sections of varying lengths in a single composite sewer rod, periods of lost motion will be encountered whenever a change in rod section length is encountered along the composite rod. Additionally, due to the continuous rotation of the composite sewer rod in connection with feed thereof, there is a tendency for whipping of the region of the rod being operated upon. Finally, -a conventional sewer cleaning machine is incapable of handling rod sections of varying lengths indiscriminately coupled together inasmuch as the danger of seating of a given pusher block directly upon a coupler is present and this results in breakage of the chain conveyor or jamming of the machine. To obviate this last-mentioned contingency, it is necessary with a conventional sewer cleaning machine to utilize a composite sewer rod in which the various rod sections are uniform in length and to make a chain substitution whenever there is a change in the character of the composite sewer rod to be handled. A conventional machine is incapable of accommodating a composite sewer cleaning rod having rod sections of varying lengths indiscriminately coupled together.

The present invention is designed to overcome the above-noted limitations that are attendant upon the construction and use of a conventional sewer cleaning machine of the type or character under consideration and, toward this end, the invention contemplates the provision in such a machine of a novel drive unit which employs chain-driven pusher blocks and wherein the action of such pusher blocks is augmented by the use of a series of stabilizing blocks on a second endless chain conveyor, the two chain conveyors having juxtapositioned cooperating straight reach sections wherein the pusher blocks and stabilizer blocks are brought together in groups for cooperation with the region of composite sewer cleaning rod undergoing feeding in such a manner that lost motion between the pusher blocks and couplers is reduced to a minimum, that whipping or other lateral displacement of the rod region being operated on is positively prevented, that various interchanges of rod sections may be resorted to without requiring machine alteration or modification, and that under certain circumstances, a composite sewer cleaning rod having rod sections of varying lengths indiscriminately coupled together may be accommodated.

The provision of a sewer cleaning machine drive unit which is capable of ease of installation in an existing machine as a replacement unit; one which is capable of ease of assembly for purposes of inspection, replacement, or repair of parts; one which is rugged and durable and, therefore, will withstand rough usage; one which may be manufactured at a relatively low cost; and one which, otherwise, is well-adapted to perform the services required of it, are further desirable features which have been borne in mind in the production and development of the present invention.

In the accompanying four sheets of drawings forming a part of this specification, one illustrative embodiment of the invention has been illustrated.

In these drawings:

FIG. 1 is a fragmentary side elevational view of a. sewer cleaning machine embodying the improved rod drive unit of the present invention, certain parts of the machine being broken away and other parts being shown in section in order more clearly to reveal the nature of the invention;

FIG. 2. is a fragmentary top plan view of the structure shown in FIG. 1;

FIG. 3 is a greatly enlarged fragmentary side elevational view of a portion of the rod drive unit in the vicinity of the cooperating reach sections of the drive chains which are employed or utilized in connection with the invention;

FIG. 4 is a fragmentary side elevational View of a portion of the structure shown in FIG. 2;

FIG. 5 is an enlarged sectional view taken on the line 55 of FIG. 2;

FIG. 6 is a fragmentary and further enlarged detail sectional view of the central portion of the structure shown in FIG. 5;

FIG. 7 is a side elevational view, schematic in its representation, illustrating the disposition or arrangement of certain rod'pusher and stabilizing blocks employed in connection with the present invention when a sewer cleaning rod having rod sections of a given unit length is undergoing feeding by the drive unit; and

FIG. 8 is a schematic view similar to FIG. 7 but showing the distribution or arrangement of rod-pusher and stabilizing blocks when a sewer cleaning rod having rod sections of varying lengths is fed by the drive unit.

Referring now to the drawings in detail and in particular to FIG. 1, the improved drive unit comprising the present invention has been designated in its entirety by the reference numeral 10, and it is shown as being operatively installed in a machine which assumes the form of a trailer vehicle and incorporates a power-driven storage reel from which a comparatively great length of com posite sewer cleaning rod in the form of coupled sewer rod sections may be payed out to a sewer pipe undergoing cleaning or retracted back into the reel, the reel being continuously rotated during feeding or retraction of the composite rod so that the latter will rotate within the sewer pipe undergoing treatment. A machine of this general type is commonly referred to as a sewer rodder. The function of the present drive unit 10 is to effect axial shifting of the composite rod in either direction while at the same time allowing for rotation thereof. Although the drive unit 10 has been specifically illustrated in connection with a sewer rodder of the trailer vehicle type, the unit is equally applicable to other types of sewer rodders, for example, sewer rodders which are embodied in self-propelled or tractor type vehicles. Irrespective, however, of the particular environment Within which the present drive unit may be installed or utilized, the essential features thereof are at all times preserved.

Briefly, the trailer vehicle with which the drive unit 18 is shown involves in its general organization a chassis or framework 12, the rear end of which is supported by means of wheels 14 and the front end of which is provided with conventional attaching means (not shown) whereby the vehicle may be attached to and drawn by a tractor or other propelling vehicle. The trailer vehicle has been fragmentarily shown herein, only such details as bear a relationship to the rod driving unit 15} being illustrated. At the rear end of the vehicle framework 12 there is disposed a relatively large and generally frustoconical rod storage reel or cage 16, the large base of which faces rearwardly and carries a trunnion 18 which rotates in a fixed bearing 29 at the rear end of the framework 12. The small base of the frusto-con-ical cage 16 carries a funnel 22 which serves as a support for said small base of the cage and is rotatable in a fixed bearing 24 on the framework 12.

The cage 16 is adapted to receive therein in coiled fashion the composite sewer cleaning rod which is associated with the machine, this composite rod being comprised of a large number of elongated rod sections R (see FIG. 3) which are joined together in end-to-end relationship by intervening couplers C having lock nuts N at the ends thereof, the lock nuts having screw threads of reverse pitch. The composite sewer rod is of comparatively great length and the various rod sections R are supplied in standard lengths, preferably in lengths which are multiples of a given unit length. For illustrative purposes herein, it may be assumed that the rod sections R are supplied in two lengths, namely 36-inch lengths and 48-inch lengths, these lengths being multiples of twelve inches. As will be pointed out in detail presently when the nature of the drive unit It} is made clear, when multiple lengths of this character are employed, the drive unit 10 may be supplied for convenient change-over operations so that it will accommodate an elongated composite sewer rod which is made up of couplers C and rod sections R with the latter being of uniform lengths in either size, or with the lengths being unequal and indiscriminately mixed. The individual rods R are relatively rigid, but they are capable of such limited flexing that when a large number of them are assembled to constitute a composite sewer cleaning rod, the rod as a whole is sufficiently flexible to enable it to become coiled in both helical and involute fashion in the manner of a wound spool or reel within the rear region of the cage 16, such coiling taking place automatically and progressively as the composite sewer rod is fed back by the unit 10 into the cage through the funnel 22, and the sewer rod becoming progressively uncoiled as the sewer rod is payed out by the unit 1%) from the cage 16 through the funnel.

As is customary in connection with a sewer cleaning machine of the character under consideration, a suitable boring, reaming or other tool is adapted to be applied to the leading end of the composite sewer rod for entry into the sewer pipe undergoing treatment. This tool, together with the portion of the composite sewer rod which has been payed out from the cage 16 is adapted to be rotated about its axis, such rotation being accomplished by effecting continuous rotation of the cage 16 in one direction. As will be described in greater detail presently, the improved drive unit 16 of the present invention is disposed immediately in front of the cage 16, receives the composite rod as it issues directly from the funnel 22, impels the same forwardly, and ejects the same through a throat piece 3% during paying out operations for entry into the sewer pipe. During retracting operations, the drive unit 19 engages the composite sewer rod, draws the same rearwardly through the throat pieces 3%, and forces the same through the funnel 22 and into the cage 16 where it becomes coiled for storage within the rear regions of the cage.

The drive mechanism by means of which the cage 16 is rotated forms no part of the present invention and, consequently, it will be described only briefly herein. The cage 16 is provided with a relatively large sheave 32 in the medial longitudinal region thereof, and this sheave is connected by a dual belt 34 to the output or driving pulley 36 of a gear reduction device 38 which is suitably supported on the framework 12. The input pulley 40 of the gear reduction device 38 is connected by a belt 42 to a relatively large pulley 44 on the drive shaft 46 of a power unit 43. The latter may, if desired, be in the form of a conventional internal combustion engine. A relatively small drive pulley 50 on the shaft 46 is connected by a belt 52 to a reversing transmission mechanism 54, the purpose and function of which will be made clear presently.

A clutch mechanism 66, including a belt-tightening idler pulley 62, in cooperative relationship with the belt 42, is operable through a control rod 64, such rod being connected through a coupling 66 and a connection (not shown) to a second control rod 68. The latter is operatively connected to a brake band 70 which cooperates with a brake drum 72 on the front end of the cage 16. The arrangement of control rods is such that application of the brake mechanism consisting of the band 70 and the drum 72 will automatically effect release of the clutch mechanism 60.

The arrangement of parts thus far described is, in general, conventional in that there are at the present time on the market sewer rodders in the form of trailer type machines having power-driven rotatable cages which are designed to house composite sectional sewer rods similar to that disclosed herein and from which cages the rotating sewer rods are payed out and retracted under the in fluence of drive mechanisms. No claim is made herein to any novelty in the rotatable cage 16 or its associated drive mechanism, the novelty of the present invention consisting rather in the novel construction, combination and arrangement of parts of the sewer rod drive unit 10.

Power for actuating the drive unit 10 is supplied from the power unit 48 through a power train which includes the reversing transmission mechanism 54. The details of this power train have been disclosed only schematically herein since they constitute no part of the presentinvention.

Briefly, the aforementioned power train, in addition to the reversing transmission mechanism 54, includes an endless chain 80 which passes over a relatively small output sprocket 82 in associated relationship with the reversing transmission mechanism 54 and also over a relatively large input pulley 84 in associated relationship with a two-way, spring-loaded, torque limiting overload clutch device 86. The clutch device 86- is provided with an output sprocket 88 which is operatively connected by an endless chain 89 to the input or driving sprocket 90 of the present sewer rod drive unit 10.

Referring now additionally to 'FIGS. 2, 3, 4, and 6, briefly, the sewer rod drive unit of the present invention involves, in its general organization, a fixed housing in the form of an I-beam 100 having upstanding parallel side flanges 102, depending parallel side flanges 104, and a horizontal connecting web 106 between the inner side margins of the flanges 102 and 104. The web 106 and the upstanding flanges 102 constitute, in effect, an open upwardly presented channel housing 107 which extends longitudinally of the machine and has its. rear end in register with the funnel 22 at the front end of the cage 16 and its front end in register with the throat piece 30-. The rear end of the I-beam 100 fits between and is welded as at 188 to a pair of spaced apart upstanding side plates 110 and 112, and the front end of the I-beam fits between and is similarly welded to a pair of spaced apart upstanding side plates 114 and 116. Such plates constitute parts of the framework 12.

The two pairs of side plates 110 and 112, and 114 and 116, constitute supports for upper and lower endless chain conveyor assemblies 118 and 120, the two assemblies having cooperating substantially contiguous straight reach sections between which the rotating composite sewer. rod passes upon emergence from the funnel 2.2. As will be described in greater detail presently, these reach sections of the conveyor assemblies 118 and 120 are disposed entirely within the aforementioned channel housing 107, and are substantially coextensive with the longitudinal extent of such housing. The upper conveyor assembly 118 has associated therewith means for positively driving the composite sewer rod along and through the channel housing in either direction to cause the composite rod to be pulled through the funnel 22 and thus payed out from the cage 16, or to be pushed, so to speak, in a reverse direction into the funnel 22 and thus coiled into the cage. The terms drive and driving as employed herein are to be construed as implying axial shifting of the composite sewer rod in either direction. The lower conveyor assembly 120 has associated with it means for stabilizing the composite sewer rod as it passes axially through and along the channel housing 107.

As best seen in FIGS. 1, 4 and 5, the upper chain conveyor assembly 118 includes a drive shaft 122 which is journalled in a pair of spaced apart bearings 124. The latter are secured by bolts 126 to the upper ends of the side plates 110 and 112. The drive shaft 122 is disposed rearwardly of the I-beam 100 and at a level slightly above the level of the channel housing 107. It spans the distance between the two side plates 110 and 112 and projects laterally outwardly on opposite sides of the plates. The previously mentioned input or driving sprocket 90 of the drive unit 10 is fixedly mounted on one of the projecting ends of the shaft 122. The upper conveyor assembly 118 further includes a driven or idler shaft 128 which is rotatably journalled in a pair of spaced apart bearings 130'. The latter are secured by bolts 132 to the upper ends of the side plates 114 and 116. The conveyor 118 is of the dual chain type and, accordingly, two side-by-side endless conveyor chains 134 extend around a pair of sprockets 136 on the shaft 122 and around similar sprockets 138 on the idler shaft 128. The idler shaft 128 isdisposed for- Wardly of the channel housing 107 and slightly above the level thereof, the arrangement of the shafts 12.8 and 122 and the diameters of the various sprockets 136 and 138 being such that the lower reach sections of the conveyor chains 134 extend through the channel housing 107 at a level slightly below the level of the upper edges of the side flanges 102 of the I-beam 100.

The lower conveyor assembly 120 includes a drive shaft 140 (see FIGS. 4 and 5) which is journalled in a pair of spaced apart bearings 142. The latter are secured by bolts 144 to the upper ends of the side plates 1'10 and 112. The assembly also includes a driven or idler shaft 146 which is journalled in a pair of spaced apart bearings 148. The latter are secured by bolts 150 to the upper ends of the side plates 114 and 116. The conveyor assembly 12.0 is of the single chain type and, accordingly, an endless chain 152 extends around the sprockets 154 and 156 on the shafts 140 and 146, respectively. The disposition of the shafts @140 and 146 and the diameters of the sprockets 154 and 156 are such that the upper reach section of the chain 152 passes through the channel housing '107 of the I-beam 100 at a level slightly below the level of the lower reach sections of the chains 134 of the upper chain conveyor assembly 118. The two conveyor chains 134 and 152 are constrained to move in unison and at the same rate of travel by means of mating gears 157 and 158 (see FIGS. 2 and 5) which are fixed to certain adjacent projecting ends of the shafts 122 and 140.

Referring now to FIGS. 3, 5 and 6, at predetermined spaced points along the chains 134 of the upper conveyor are rod-impelling pusher blocks 160 having tapered yokes 162 which are adapted closely to overlie and straddle such sewer rod sections R as may be encountered by the pusher blocks as they enter the channel housing at either end thereof when moving in opposite directions respectively. The yoke sides terminate in relatively narrow rodconfining notches 163 within the confines of which the rods are disposed when the pusher blocks 160 are effectively in contact with the couplers C. As the chains 134 move in either direction, the pusher blocks 160 will engage the end faces of the locking nuts N of the various couplers C and impel the couplers and, consequently, the entire composite sewer rod in one direction or the other, depending upon the direction of movement of the chains 134. It is to be noted at this point that when a given rotating coupler C is being pushed by one of the pusher blocks 160 to the left, as viewed in FIG. 3, for example, so that the sewer rod is moved forwardly, the adjacent end face of the nut N is engaged in a manner tending to tighten the nut in the coupler C, this being due to the left-hand screw thread on the nut. Conversely, when a given rotating coupler is being pushed by a given pusher block 160 in the opposite direction, there also will be a tendency for the adjacent nut N to become tightened in its respective coupler due :to the right-hand screw thread on the nut.

The various pusher blocks 160 project upwardly a slight distance above the level of the upper regions of the chains 134 when in the lower reach sections thereof and are confined between the opposed longitudinal edges of a pair of spaced apart longitudinally extending centering plates 164 (see FIG. 6) which are secured to the underneath face of an elongated horizontal longitudinally extending reaction plate '166. The latter overlies and is spaced above the web 106 of the I-beam 100 and is substantially coextensive with the straight reach sections of the two conveyor assemblies 118 and 120. Said reaction plate 166 is maintained spaced above the web 106 by means of tubular spacer posts 168 which are clamped in position by bolt assemblies 169. The upper faces of the pusher blocks 160 slide and find reaction support upon the underneath face of the reaction plate 166 as they travel in the straight lower reach sections of the chains 134 and pass through the upwardly-facing channel housing 107 in either direction. Lateral shifting or sway of the various rod sections R which are captured within the yoke portions of the effective or operative pusher blocks 160 is prevented by the centering action of the two plates 164 which straddle the extreme upper regions of the pusher blocks.

Still referring to FIGS. 3, and 6, the upper reach section of the chain 152 of the lower conveyor assembly 120 passes through the channel housing 107 of the I-beam 100 directly beneath the lower reach sections of the chains 134, and at predetermined spaced points along the chain 152 there are secured -a plurality of coupling stabilizer blocks 170. The upper faces of the stabilizer blocks 170 are provided with shallow troughs 172 (see FIG. 6) which are designed for seating engagement with the underneath sides of the various couplers C as they pass through the channel housing 107. The straight upper reach section of the chain 152 slides upon an elongated longitudinally extending combined wear and reaction rail 174 which is secured by bolts 176 to the upper surface of the central portion of the web 106 of the I-beam 160. Limited portions of the individual chain links straddle the rail 174 and prevent chain side sway. The various pusher blocks 160 and stabilizer blocks 170, when operatively engaged with the portion of the composite sewer rod that is within the channel housing 107, thus serve to inhibit whipping or other lateral displacement of the rod.

According to the present invention, the disposition of the various pusher blocks 160 on the chains 134 and the disposition of the various stabilizer blocks 170 may be varied in the interests of attaining the most effective cooperation between these blocks for sewer rod impelling purposes. Generally speaking, the pusher blocks function to engage the nuts N, and by their engagement therewith, to push the associated couplers C and, consequently, the sewer rod as a whole in one direction or the other through the channel housing 107. In order etfectively to do this, it is essential that the particular rod section R which is straddled by the yoke 162 of any given pusher block 160 be wholly disposed within the yoke and, accordingly, it is a function of the various stabilizer blocks 170 to engage the rotating couplers C, and by the upward thrust thus applied thereto, to maintain the adjacent ends of the rods in an elevated position so that they will enter and remain Within the narrow notches 163 at the bases of the yokes of the pusher blocks. It is another function of the stabilizer blocks 170 to cooperate with the pusher blocks and inhibit whipping or other lateral displacement of the portion of the composite sewer rod which, at any given time, is within the confines of the channel housing 107.

To render the pusher blocks 160 and stabilizer blocks 170 effective as briefly outlined above, consideration must be given to the lengths of the individual rod sections R and of the couplers C, as well as to the sequential arrangement of the rod lengths in the composite sewer rod. If, for example, all of the rod sections R are equal in length, the most effective disposition of the pusher blocks 160 and stabilizer blocks 170 on the chains 134 and 152, respectively, will be had by causing the pusher blocks on the chain 134 to be arranged in spaced pairs as shown in FIG. 7 with the distance between the blocks of each pair being slightly longer than the over-all length of a coupler C including the associated nuts N, and with the stabilizer blocks also being arranged in pairs. Since the chains 134 and 152 operate in timed relationship and are of equal extent, it is possible to cause the pairs of blocks 160 and 170 to enter, travel through, and leave the channel housing 107 in groups of four blocks, such groups being designated in the schematic representation of FIG. 7 at G and each group comprising two pusher blocks and two stablizer blocks in which each pusher block is spaced from a stabilizer block by a relatively small distance.

For the most elfective cooperation with the composite sewer rod and in order that substantially instantaneous reversing action may be attained when the reversing transmission is operated to change from a paying-out to a reeling-in operation, each coupling is caused to be straddled closely by a pair of pusher blocks as the coupling enters the operating region of the drive unit. The composite sewer rod is initially set so that as it enters the channel housing 107, it will be straddled by two of the pusher blocks and supported on its underneath side by one of the stabilizer blocks.

Where the individual rod sections R of the composite sewer rod are of unequal length and indiscriminately disposed in the sewer rod with no particular pattern of sequential arrangement, a different disposition of the pusher blocks 160 and the stabilizer blocks 170 on the chains 34 and 152, respectively, will be resorted to. An example of such a situation is illustrated schematically in FIG. 8 wherein a combination of rod section lengths (not shown) which are multiples of a given unit or common denominator length are employed. In the illustrated example, the rod sections R are multiples of one-foot lengths, some of the rod sections being three feet long and others being four feet long. In such a situation, the pusher blocks 160 are positioned on the chains 134 so that their center-to-center distance is equal to selected unit lengths, the unit being the greatest common denominator of the various rod lengths involved. The stabilizer blocks 170 are, in number, double the number of pusher blocks 160 and are disposed in pairs, with the distance between adjacent blocks of each pair being slightly greater than the over-all length of a coupler C, including the associated nuts N. The center-to-center distance between adjacent pairs of blocks 170 is equal to the center-tocenter spacing between adjacent blocks 160. The chains 134 and 152 are so correlated that the pusher blocks 160 and the stabilizer blocks 170 enter the channel housing 107, pass through this housing, and leave the same in groups G of three blocks each, including one pusher block 160 and two stabilizer blocks 170. The stabilizer locks will, upon entering the working area, assume positions on opposite sides of a pusher block and in close proximity thereto. Thus, regardless of the direction of movement, one of the pusher blocks will substantially immediately engage a coupler as it enters the working area. At the same time, one of the stabilizer blocks 170 will enter upon and support the underneath side of the coupler at a region adjacent to the end of the coupler which is undergoing impelling by the adjacent pusher block of the group. The other stabilizer block of the group G will lie on the trailing side of the coupler and remain ineffective for any useful purpose as far as the coupler is concerned although it serves to a certain extent to restrain lateral whipping of the rod. Such a situation is portrayed in FIG. 3.

If the direction of impelling movement is reversed so that the cooperating straight reach sections of the chains 134 and 152 move to the right as seen in FIG. 8, a very short period of lost motion will be encountered, after which one of the pusher blocks 160 will engage one nut N of a coupler C to impel the composite sewer rod to the right, while an adjacent stabilizer block 170 of the group G will have previously engaged the coupler C adjacent to the end thereof which is engaged by the pusher block 160 of the group.

To this accommodate any combination of rod sections R of the two lengths selected for illustrative purposes herein, i.e., three and four-foot lengths, the center-tor center distance between the various driving and driven sprockets must be equal to or greater than the longest rod undergoing feeding. As is the case in connection with the example portrayed in FIG. 7, the center-to-center distance between adjacent groups may be a fraction such as one-half of the center-to-center distance between adjacent couplers C.

Preferably, in either of the examples selected for illustration in FIGS. 7 and 8, respectively, the disposition of the pusher blocks 160 on the chains 134 is such that all of the blocks will come into play at least once during two complete endwise shifting movements of the chains. In the situation represented by FIG. 7, if an odd number of pusher blocks 160 is employed on the chains 134, depending upon what multiple length spacing is employed as outlined above, a given pusher block 160 will engage a coupler C each time it passes through the channel housing 107, or such pusher block will engage a coupler C on successive alternate passes through the channel housing. At such time as the pusher blocir does not engage a coupling, it will serve to restrain a rod section from excessive lateral movement in between couplings. In this manner, wear upon the blocks is equalized.

From the above description, it is believed that the nature and construction, as well as the operation of the herein-disclosed drive unit, will be readily apparent. It is to be distinctly understood that the invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention. For example, the drive unit is not necessarily limited to use in connection with sewer cleaning machines of the tractionally supported wheeled vehicle type. If desired, the drive unit of the present invention may, by suitable modification, be adapted for use in connection with household or building pipe-cleaning equipment or with various wire-feeding instrumentalities. It is not necessary that a common power supply be employed for both rotation of the composite sewer rod being operated upon since a separately-powered drive means for the unit may be employed if desired. It is not essential that the composite rod being operated upon be rotated since feeding of the length will take place regardless of whether rotation thereof takes place or not. In certain instances, a belt drive may be substituted where a chain drive has been disclosed herein and vice versa. Therefore, only insofar as the invention has particularly been pointed out in the accompanying claims is it to be limited.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. A drive unit adapted for use in a sewer cleaning machine or the like and operative selectively to feed in opposite directions and axially to and from an aperture an elongated composite sectional rod in the form of a series of alternately arranged rod sections and couplers, said unit comprising upper and lower endless chain and sprocket conveyors arranged one above the other and having their respective chains provided with opposed straight reach sections disposed in coextensive contiguity and horizontal register with the aperture and adapted to receive the composite rod therebetween for rods-impelling purposes, a series of uniform pusher blocks on the chain of one conveyor and selectively engageable with the leading and trailing end faces of the couplers for impelling the rod to and from the aperture, a series of stabilizer blocks on the chain of the other conveyor and engageable with the side faces of the couplers to restrain lateral displacement of the rod from its axial path of movement, the pusher blocks on the chain of said one conveyor being arranged in spaced pairs with the pusher blocks of each pa'nbeing spaced apart a distance slightly greater than the over-all axial extent of a coupler, the stabilizer blocks on the chain of said other conveyor being arranged in spaced pairs corresponding in number to the pairs of push- 1t) er blocks and with the stabilizer blocks of each pair being so spaced apart and located that, during passage of said pusher and stabilizer blocks along the contiguous reach sections of their respective conveyors, said stabilizer blocks of each pair are positioned in the space between, and in close proximity to, the pusher blocks of an adjacent pair of pusher blocks, and interconnecting drive means between said conveyors constraining the chains thereof to move in unison and in the same direction along the path of travel of the composite rod.

2. A drive unit as set forth in claim 1 and wherein the center-to-center distances between adjacent pairs of blocks on the chain of each conveyor are equal, and wherein there are an odd number of pairs of blocks on the chain of each conveyor.

3. A drive unit adapted for use in a sewer cleaning machine or the like and operative selectively to feed, in opposite directions and axially to and from an aperture, an elongated composite sectional rod in the form of a series of alternately arranged rod sections and couplers, said unit comprising a pair of endless chain and sprocket conveyors arranged one above the other and having their respective chains provided with opposed straight reach sections disposed in coextensive contiguity and horizontal register with the aperture and adapted to receive the composite rod therebetween for rod-impelling purposes, a series of pusher blocks on the chain of one conveyor and selectively engageable with the leading and trailing end faces of the couplers for impelling the rod to and from the aperture respectively, said pusher blocks having trough-like guide channels therein loosely receivable over the rod sections between adjacent couplers as the blocks move into the reach section of their respective chain from either end thereof, a series of stabilizer blocks connected to the chain of the other conveyor and having trough-like seating surfaces engageable with the side faces of the couplers as said stabilizer blocks move into the reach section of their associated chain for forcing the couplers in a direction to cause the adjacent rod sections to seat against the bottoms of the guide channels in which they are disposed, and interconnecting drive means between said conveyors constraining the chains thereof to move in unison and in the same direction along the path of travel of the composite rod.

4. A drive unit as set forth in claim 3 and wherein the spacing :of said pusher and stabilizer blocks on their respective chains is such that collectively the blocks enter the opposed reach sections in groups for travel in the direction of rod movement, each group including at least one pusher block and an adjacent stabilizer block spaced therefrom a distance less than the over-all axial extent of a coupler.

5. A drive unit adapted for use in a sewer cleaning machine or the like and operative selectively to feed, in opposite directions and axially to and from an aperture, an elongated composite sectional rod in the form of a series of alternately arranged rod sections and couplers, said unit comprising upper and lower endless chain and sprocket conveyors arranged one above the other and having their respective chains provided with opposite straight reach sections disposed in coextensive contiguity and horizontal register with the aperture and .adapted to receive the composite rod therebetween for rod-impelling purposes, a series of pusher blocks mounted on the chain of the upper conveyor and selectively engageable with the leading and trailing end faces of the couplers for impelling the rod to and from the aperture, a series of stabilizer blocks mounted on the chain of the lower conveyor and engageable with the underneath faces of the couplers to restrain lateral displacement of the rod from its axial path of movement, an upper reaction member above the straight reach section of the chain of the upper conveyor and substantially coextensive therewith, said pusher blocks being slidable axially on the underneath face of said reaction member, a lower reaction member below the straight reach section of the chain of the lower conveyor and substantially coextensive therewith, the chain of the lower conveyor being slidable on the upper face of said lower reaction member, and interconnecting drive means between said conveyors constraining the chains thereof to move in unison and in the same direction along the path of travel of the composite rod.

6. A drive unit as set forth in claim and including, additionally, interengaging shoulders provided on the pusher blocks and upper reaction member respectively, having running engagement with each other and adapted to prevent lateral shifting of the pusher blocks.

7. A drive unit as set forth in claim 5 and including, additionally, interengaging shoulders provided on the chain of the lower conveyor and the lower reaction member respectively, having running engagement with each other, and adapted to prevent lateral shifting of the stabilizer blocks.

8. A drive unit as set forth in claim 5 and including, additionally, interengaging shoulders provided on the pusher blocks and upper reaction member respectively, having running engagement with each other, and adapted to prevent lateral shifting of the pusher blocks, and interengaging shoulders provided on the chain of the lower conveyor and the lower reaction member respectively, having running engagement with each other, and adapted to prevent lateral shifting of the stabilizer blocks.

9. A drive unit adapted for use in a sewer cleaning machine or the like and operative selectively to feed, in opposite directions and axially to and from an aperture, an elongated composite sectional rod in the form of a series of alternately arranged rod sections and couplers, said unit comprising upper and lower endless chain and sprocket conveyors arranged one above the other and having their respective chains provided with opposed straight reach sections disposed in coextensive contiguity and horizontal register with the aperture and adapted to receive the composite rod therebetween for rod-impelling purposes, said upper conveyor including two spaced apart parallel sprocket-driven chains including transverse linksupporting pins common to both chains, a series of pusher blocks supported on said pins between the two chains and selectively engageable with the leading and trailing end faces of the couplers for selectively impelling the rod to and from the aperture, a series of stabilizer blocks on the chain of the lower conveyor and engageable with the underneath faces of the couplers to restrain lateral displacement of the rod from its axial path of movement, and interconnecting drive means between said conveyors constraining the chains thereof to move in unison and in the same direction along the path of travel of the composite rod.

10. A drive unit as set forth in claim 9 and including, additionally, an upper reaction member positioned above the straight reach section of the upper conveyor and substantially coextensive therewith and adapted to have the pusher blocks slide axially on the underneath face thereof, and a lower reaction member disposed below the straight reach section of the chain of the lower conveyor and substantially coextensive therewith, and adapted to have the chain of the lower conveyor slide on the upper face thereof.

11. A drive unit as set forth in claim 10 and including, additionally, interengaging shoulders provided on the pusher blocks and the upper reaction member respectively, having running engagement with each other, and adapted to prevent lateral shifting of the pusher blocks.

12. A drive unit as set forth in claim 10 and including, additionally, interengaging shoulders provided on the chain of the lower conveyor and the lower reaction member respectively, having running engagement with each other, and adapted to prevent lateral shifting of said chain as well as the stabilizer blocks that are carried thereby.

13. A drive unit as set forth in claim 10 and including, additionally, interengaging shoulders provided on the pusher blocks and upper reaction member respectively, having running engagement with each other, and adapted to prevent lateral shifting of the pusher blocks, and interengaging shoulders provided on the chain of the lower conveyor and the lower reaction member, having running engagement with each other, and adapted to prevent lateral shifting of said chain as well as the stabilizer blocks that are carried thereby.

14. A drive unit adapted for use in a sewer cleaning machine or the like and operative selectively to feed, in opposite directions and axially to and from an aperture, an elongated composite sectional rod in the form of a series of alternately arranged rod sections and couplers, said unit comprising an upwardly opening elongated channel-defining member through which the composite rod is adapted to move cndwise, upper and lower endless chain and sprocket conveyors arranged one above the other and having their respective chains provided with opposed straight reach sections disposed in coextensive contiguity and horizontal register with the aperture and adapted to receive the composite rod thcrebetween for rod-impelling purposes, said contiguous straight reach sections passing longitudinally along and Within the channel defined by said member, said upmr conveyor including two sideby-side but spaced apart parallel sprocket-driven chains including transverse link-supporting pins common to both chains, a series of pusher blocks supported on the pins between the two chains and selectively engageable with the leading and trailing end faces of the couplers within the channel for rod-impelling purposes, a series of stabilizer blocks on the chain of the lower conveyor and engageable with the underneath faces of the couplers within the channel to restrain lateral displacement of the rod from its axial path of movement, interconnecting drive means between said conveyors constraining the chains thereof to move in unison and in the same direction along the path of travel of the composite rod, and a reaction plate removably disposed within the upper portion of the channel and above the straight reach section of the upper conveyor and substantially coextensive therewith, said pusher blocks being slidable axially on the underneath face of said reaction plate.

15. A drive unit as set forth in claim 14 and including, additionally, interengaging shoulders provided on the pusher blocks and the reaction plate respectively, having running engagement with each other, and adapted to prevent lateral shifting of the pusher blocks.

16. A drive unit adapted for use in a sewer cleaning machine or the like and operative selectively to feed, in opposite directions and axially to and from an aperture, an elongated composite sectional rod in the form of a series of alternately arranged rod sections and couplers, said unit comprising an upwardly opening elongated channel-deiining member through which the composite rod is adapted to move cndwise, upper and lower endless chain and sprocket conveyors arranged one above the other and having their respective chains provided with opposed straight reach sections disposed in coextensive contiguity and horizontal register with the aperture and adapted to receive the composite rod therebetween for rod-impelling purposes, said contiguous straight reach sections passing longitudinally along and within the channel defined by said member, said upper conveyor including two side-byside but spaced apart parallel sprocket-driven chains including transverse link-supporting pins common to both chains, a series of pusher blocks supported on the pins between the two chains and selectively engageable with the leading and trailing end faces of the couplers within the channel for rod-impelli-ng purposes, a series of stabilizer blocks on the chain of the lower conveyor and engageable with the underneath faces of the couplers within the channel to restrain lateral displacement of the rod from its aXial path of movement, interconnecting drive means between said conveyors constraining the chains thereof to move in unison and in the same direction along the path of travel of the composite rod, a reaction plate removably disposed within the upper portion of the channel and above the straight reach section of the upper conveyor and substantially coextensive therewith, said pusher blocks being slid-able axially 011 the underneath face of said reaction plate, interengaging means provided on the pusher blocks and the reaction plate respectively, having running engagement with each other, and adapted to prevent lateral shifting of the pusher blocks, a reaction member below the straight reach section of the chain of the lower conveyor and substantially coextensive therewith,

14 the chain of the lower conveyor being slidable 0n the upper face of said reaction member, and interengaging means on the chain of the lower conveyor and said reaction member respectively for preventing lateral shifting of the chain. and consequently the stabilizer blocks that are carried thereby.

References Cited in the file of this patent UNITED STATES PATENTS 1,653,215 Koehendorfer Dec. 20, 1927 2,383,843 Blane Aug. 28, 1945 2,544,256 Ciaccio Mar. '18, 1951 2,904,885 Seeley Apr. =18, 1953 

1. A DRIVE UNIT ADAPTED FOR USE IN A SEWER CLEANING MACHINE OR THE LIKE AND OPERATIVE SELECTIVELY TO FEED IN OPPOSITE DIRECTIONS AND AXIALLY TO AND FROM AN APERTURE AN ELONGATED COMPOSITE SECTIONAL ROD IN THE FORM OF A SERIES OF ALTERNATELY ARRANGED ROD SECTIONS AND COUPLERS, SAID UNIT COMPRISING UPPER AND LOWER ENDLESS CHAIN AND SPROCKET CONVEYORS ARRANGED ONE ABOVE THE OTHER AND HAVING THEIR RESPECTIVE CHAINS PROVIDED WITH OPPOSED STRAIGHT REACH SECTIONS DISPOSED IN COEXTENSIVE CONTIGUITY AND HORIZONTAL REGISTER WITH THE APERTURE AND ADAPTED TO RECEIVE THE COMPOSITE ROD THEREBETWEEN FOR ROD-IMPELLING PURPOSES, A SERIES OF UNIFORM PUSHER BLOCKS ON THE CHAIN OF ONE CONVEYOR AND SELECTIVELY ENGAGEABLE WITH THE LEADING AND TRAILING END FACES FO THE COUPLERS FOR IMPELLING THE ROD TO AND FROM THE APERTURE, A SERIES OF STABILIZER BLOCKS ON THE CHAIN OF THE OTHER CONVEYOR AND ENGAGEABLE WITH THE SIDE FACES OF THE COUPLERS TO RESTRAIN LATERAL DISPLACEMENT OF THE ROD FROM ITS AXIAL PATH OF MOVEMENT, THE PUSHER BLOCKS ON THE CHAIN OF SAID ONE CONVEYOR BEING ARRANGED IN SPACED PAIRS WITH THE PUSHER BLOCKS OF EACH PAIR BEING SPACED APART A DISTANCE SLIGHTLY GREATER THAN THE OVER-ALL AXIAL EXTENT OF A COUPLER, THE STABILIZER BLOCKS ON THE CHAIN OF SAID OTHER CONVEYOR BEING ARRANGED IN SPACED PAIRS CORRESPONDING IN NUMBER TO THE PAIRS OF PUSHER BLOCKS AND WITH THE STABILIZER BLOCKS OF EACH PAIR BEING SO SPACED APART AND LOCATED THAT, DURING PASSAGE OF SAID PUSHER AND STABILIZER BLOCKS ALONG THE CONTIGUOUS REACH SECTIONS OF THEIR RESPECTIVE CONVEYORS, SAID STABILIZER BLOCKS OF EACH PAIR ARE POSITIONED IN THE SPACE BETWEEN, AND IN CLOSE PROXIMITY TO, THE PUSHER BLOCKS OF AN ADJACENT PAIR OF PUSHER BLOCKS, AND INTERCONNECTING DRIVE MEANS BETWEEN SAID CONVEYORS CONSTRAINING THE CHAINS THEREOF TO MOVE IN UNISON AND IN THE SAME DIRECTION ALONG THE PATH OF TRAVEL OF THE COMPOSITE ROD. 